1. Field of the Invention
This invention pertains to novel apparatus, and a method of use, for recovering diesel-quality fuel from produced crude oil.
2. Description of the Prior Art
Refineries around the world have used fractional distillation techniques to isolate and recover certain hydrocarbons or hydrocarbon cuts from crude oil. Such refineries process huge volumes of crude oil through a complex network of piping, distillation columns, hydrocarbon cracking units, etc., to produce hydrocarbon fuel (e.g., diesel, gasoline, etc.) and other products.
Diesel fuel oils, typically referred to as "diesel," are classified as Grade No. 1-D, Grade No. 3-D and Grade No. 4-D depending upon their volatility, flash point, viscosity, pour point, cloud point, ash content, cetane number, and other physical properties. A "diesel-quality fuel" will be a hydrocarbon liquid having similar properties. Each of these fuel oils can be used as fuels for internal combustion engines, although one grade may be better than the others depending upon the engine speed and load on the engine. See, for example, Kirk-Othmer Encyclopedia of Chemical Technology, Third Edition, Volume 11, pages 682-689 (1980) for an expanded discussion of diesel fuels.
Grade 2-D diesel fuel is used in many diesel engines in the oil and gas industry to generate energy for turbines and other pieces of equipment. It is also used as fuel for other fired equipment to provide process and utility heat.
Unfortunately, many of these diesel engines are at remote locations (e.g., offshore drilling platforms) where it is difficult and/or costly to supply the diesel fuel for their operation. In such situations, fuel for most remote locations is usually produced or purchased natural gas, when it is available. Alternative fuels are natural gas liquids (NGLs), diesel, and in some instances crude oil. Diesel fuel is typically transported to the location and stored for consumption. The transportation costs are expensive and storage space is sometimes in very short supply (e.g., on offshore drilling or production platforms).
Thus, one of the objects of this invention is to produce a diesel-quality fuel using a system (apparatus) designed to minimize equipment weight and space.